Method of influencing the cis/trans isomer ratio of isophoronediamine in its preparation from isophoronenitrile

US5583260A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Thomas Haas · Munster, DE
• Dietrich Arntz · Oberursel, DE
• Dieter Most · Bruchköbel, DE

Key dates

• Filing date: Dec 22, 1994
• Grant date: Dec 10, 1996
• Expiry date: Dec 22, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2601/14
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A method of controlling the cis/trans isomer ratio in the preparation of isophoronediamine by the aminating hydrogenation of isophoronenitrile in the presence of ammonia, H.sub.2 and a catalyst. The reaction takes place in two temperature steps, initially at 10.degree. to 90.degree. C. and then at above 90.degree. to 150.degree. C. with a temperature difference of at least 30.degree. C. between the two steps, the contact time being shorter in the first step than in the second. The cis/trans ratio is increased by lowering the temperature of the first step.